Guangying Du

Antidepressant-like effects of the extract from Cimicifuga foetida L.

ETHNOPHARMACOLOGICAL RELEVANCE Cimicifuga foetida L., a traditional Chinese medicine, has been developed for the treatment of perimenopausal symptoms including depression in China (Brand name: XIMINGTING(®), XMT). The primary active constituents are believed to be the triterpene glycosides. Nevertheless, there are no studies about the antidepressant-like effects of XMT in rodents. AIMS OF THE STUDY The present study aimed to evaluate antidepressant-like effects of XMT. MATERIALS AND METHODS Antidepressant-like activity of XMT was studied using forced swimming test (FST) and tail suspension test (TST) in female mice, as well as chronic mild stress (CMS) procedure in female rats. In addition, 5-hydroxytryptophan (5-HTP)-induced head-twitch test and yohimbine toxicity potentiation test in female mice were conducted to propose the possible serotonergic or noradrenergic mechanisms in the antidepressant-like effects of XMT. In mice, XMT was administrated acutely and for 7 consecutive days (20, 40 and 80 mg/kg/day, p.o.); and in rats for 28 consecutive days (10, 20 and 40 mg/kg/day, p.o.). RESULTS XMT significantly reduced immobility duration in FST and TST without affecting locomotor activity, increased swimming and climbing durations in FST, and enhanced 5-HTP-induced head-twitch response while did not affect yohimbine-induced lethality in female mice. XMT also normalized the inhibition of sucrose intake and decreased the levels of plasma adrenocorticotropic hormone and serum corticosterone and adrenal gland weight in CMS-treated female rats. CONCLUSIONS These data indicate XMT processes antidepressant-like properties in rodents, which could be related to its serotonergic and noradrenergic activation and normalization of the hypothalamic-pituitary-adrenal axis.

Ocotillol Enhanced the Antitumor Activity of Doxorubicin via p53-Dependent Apoptosis

The use of doxorubicin (Dox) was severely constrained by dose-dependent side effects, which might be attenuated by combining a “sensitizer” to decrease its cumulative dosage. In this study, it was investigated whether ocotillol could enhance the antiproliferation activity of Dox. MTT assays and xenograft tumor model were firstly conducted to evaluate the effect of ocotillol on the antitumor activity of Dox. Flow cytometry and Hoechst staining assays were then performed to assess cell apoptosis. Western blot and real-time PCR were finally used to detect the expression of p53 and its target genes. Our results showed ocotillol to enhance Dox-induced cell death in p53 wild-type cancer cells. Compared with Dox alone, Dox with ocotillol (Dox-O) could induce much more cell apoptosis and activate p53 to a much greater degree, which in turn markedly increased expression of proapoptosis genes. The enhanced cytotoxic activity was partially blocked by pifithrin-α, which might be through attenuating the increased apoptosis. Furthermore, ocotillol significantly increased the antitumor activity of Dox in A549 xenograft tumor in nude mice. These findings indicated that ocotillol could potentiate the cytotoxic effect of Dox through p53-dependent apoptosis and suggested that coadministration of ocotillol with Dox might be a potential therapeutic strategy.

NSK-01105, a novel sorafenib derivative, inhibits human prostate tumor growth via suppression of VEGFR2/EGFR-mediated angiogenesis.

The purpose of this study is to investigate the anti-angiogenic activities of NSK-01105, a novel sorafenib derivative, in in vitro, ex vivo and in vivo models, and explore the potential mechanisms. NSK-01105 significantly inhibited vascular endothelial growth factor (VEGF)-induced migration and tube formation of human umbilical vein endothelial cells at non-cytotoxic concentrations as shown by wound-healing, transwell migration and endothelial cell tube formation assays, respectively. Cell viability and invasion of LNCaP and PC-3 cells were significantly inhibited by cytotoxicity assay and matrigel invasion assay. Furthermore, NSK-01105 also inhibited ex vivo angiogenesis in matrigel plug assay. Western blot analysis showed that NSK-01105 down-regulated VEGF-induced phosphorylation of VEGF receptor 2 (VEGFR2) and the activation of epidermal growth factor receptor (EGFR). Tumor volumes were significantly reduced by NSK-01105 at 60 mg/kg/day in both xenograft models. Immunohistochemical staining demonstrated a close association between inhibition of tumor growth and neovascularization. Collectively, our results suggest a role of NSK-01105 in treatment for human prostate tumors, and one of the potential mechanisms may be attributed to anti-angiogenic activities.

Three-month subchronic intramuscular toxicity study of rotigotine-loaded microspheres in Cynomolgus monkeys

Continuous dopaminergic stimulation (CDS) is an important drug development strategy in the treatment of Parkinsons disease (PD). Rotigotine is a non-ergoline D(3)/D(2)/D(1) dopamine receptor agonist for treating PD. As a new treatment option for CDS, rotigotine-loaded microspheres (RoMS), long-acting sustained-release microspheres with poly(lactide-co-glycolide) as drug carrier, are now being evaluated in clinical trial. In the present study, the subchronic toxicity in Cynomolgus monkeys has been characterized via intramuscular administration with RoMS at 0, 10, 40 and 160 mg/kg, weekly for 3 months with a 1-month recovery period. The NOAEL was 10 mg/kg/week. One male at 160 mg/kg died from an extensive pulmonary embolism. The major toxicological effects were associated with dopamine agonist-related pharmacodynamic properties of rotigotine (e.g., hyperactivity and stereotype, decreased serum prolactin level) and foreign body removal reaction induced by poly(lactide-co-glycolide) and carboxymethycellulose sodium (e.g., increased mononuclear cells and neutrophils, thymus atrophy and vacuolar degeneration of adrenal cortex, foreign body granuloma with foam cells accumulation at injection sites and foam cells accumulation in spleen and multiple lymph sinuses). At the end of recovery period, above findings recovered to a normal level or to a certain degree except vacuolar degeneration of adrenal gland. RoMS has exhibited high safety on monkeys.

Combinatorial antitumor effects of indoleamine 2,3-dioxygenase inhibitor NLG919 and paclitaxel in a murine B16-F10 melanoma model:

Indoleamine 2,3-dioxygenase (IDO) is involved in tumor immune escape and resistance to chemotherapy, and is clinically correlated with tumor progression. IDO inhibitors show marginal efficacy as single agents; therefore, combinations of these inhibitors with other therapies hold promise for cancer therapy. The aim of this study was to investigate the synergistic antitumor effects of IDO inhibitor NLG919 in combination with different regimens of paclitaxel in a murine B16-F10 melanoma model. NLG919 increased the cytotoxic activity of paclitaxel toward B16-F10 cells in the presence of pretreatment with interferon (IFN)-γ in vitro. In B16-F10 tumor-bearing mice, NLG919 was uniformly distributed throughout tumors and decreased kynurenine levels and kynurenine/tryptophan ratios in tumors and plasma for 6–12 h. NLG919 suppressed tumor growth in a dose-dependent manner and exhibited maximum efficacy at 100 mg/kg. In combination with different regimens of paclitaxel, NLG919 displayed synergistic antitumor effects, and NLG919 did not increase the side effects of paclitaxel. Within the tumors, the percentage of CD3+, CD8+, and CD4+ T cells and secretion of IFN-γ and interleukin-2 were synergistically increased, whereas the percentage of CD4+CD25+ regulatory T cells was decreased. NLG919 can potentiate the antitumor efficacy of paclitaxel without increasing its side effects, suggesting that the combination of IDO inhibitor-based immunotherapy with chemotherapy could be a potential strategy for cancer treatment.

Preparation, pharmacokinetics, biodistribution, antitumor efficacy and safety of Lx2-32c-containing liposome.

Lx2-32c is a novel taxane that has been demonstrated to have robust antitumor activity against different types of tumors including several paclitaxel-resistant neoplasms. Since the delivery vehicles for taxane, which include cremophor EL, are all associated with severe toxic effects, liposome-based Lx2-32c has been developed. In the present study, the pharmacokinetics, biodistribution, antitumor efficacy and safety characteristics of liposome-based Lx2-32c were explored and compared with those of cremophor-based Lx2-32c. The results showed that liposome-based Lx2-32c displayed similar antitumor effects to cremophor-based Lx2-32c, but with significantly lower bone marrow toxicity and cardiotoxicity, especially with regard to the low ratio of hypersensitivity reaction. In comparing these two delivery modalities, targeting was superior using the Lx2-32c liposome formulation; it achieved significantly higher uptake in tumor than in bone marrow and heart. Our data thus suggested that the Lx2-32c liposome was a novel alternative formulation with comparable antitumor efficacy and a superior safety profiles to cremophor-based Lx2-32c, which might be related to the improved pharmacokinetic and biodistribution characteristics. In conclusion, the Lx2-32c liposome could be a promising alternative formulation for further development.

Three-month subchronic intramuscular toxicity study of rotigotine-loaded microspheres in SD rats

Continuous dopaminergic stimulation (CDS) has been an important strategy of drug development for the treatment of Parkinsons disease (PD). Rotigotine is a non-ergoline D3/D2/D1 dopamine agonist for treating PD. As a new treatment option for CDS, rotigotine-loaded microspheres (RoMS), a long-acting sustained-release microspheres for injection with poly(lactide-co-glycolide) as drug carrier, are now being evaluated in clinical trial. In this study, subchronic toxicity of RoMS in SD rats has been characterized via intramuscular administration with RoMS (0-240 mg/kg/week) on a consecutive weekly dosing schedule for 3 months followed by 1-month recovery period. The No Observed Adverse Effect Level (NOAEL) was 45 mg/kg/week. One male at 240 mg/kg died from an extensive pulmonary embolism. The major toxicological effects were associated with the dopamine agonist-related pharmacodynamic properties of rotigotine (e.g. hyperactivity and stereotype, enlarged ovary, sporadic gastric mucous membrane lesions, decreased body weight, food consumption and prolactin, and increased mononuclear cell, neutrophil granulocyte, aspartate aminotransferase and alanine aminotransferase) and foreign body removal reaction induced by poly(lactide-co-glycolide) and carboxymethycellulose sodium. At the end of recovery period, all findings had recovered to a normal level or to a certain degree except foreign body reaction at injection sites. RoMS has exhibited high safety on SD rats.

A 12-week subchronic intramuscular toxicity study of risperidone-loaded microspheres in rats.

Long-acting injectable formulations of antipsychotics have been an important treatment option to increase the compliance of the patient with schizophrenia by monitoring drug administration and identifying medication noncompliance and to improve the long-term management of schizophrenia. Risperidone, a serotoninergic 5-HT2 and dopaminergic D2 receptor antagonist, was developed to be a long-acting sustained-release formulation for the treatment of schizophrenia. In this study, 12-week subchronic toxicity study of risperidone-loaded microspheres (RMs) in rats by intramuscular injection with an 8-week recovery phase was carried out to investigate the potential subchronic toxicity of a novel long-acting sustained-release formulation. The results indicated that the dosage of 10–90 mg/kg of RM for 2 weeks did not cause treatment-related mortality. The main drug-related findings were contributed to the dopamine D2 receptor and α1-adrenoceptor antagonism of risperidone such as elevation of serum and pituitary prolactin levels and ptosis and changes in reproductive system (uterus, ovary, vagina, mammary gland, testis, seminal vesicle, epididymis, and prostate). In addition, foreign body granuloma in muscle at injection sites caused by poly-lactide-co-glycolide was observed. At the end of the recovery phase, these changes mostly returned to normal. The results indicated that RM had a good safety profile in rats.

A 12-week intramuscular toxicity study of risperidone-loaded microspheres in Beagle dogs

Long-acting formulations of antipsychotics are important treatment options to increase the compliance of schizophrenic patients. Risperidone, a 5-HT2 and dopaminergic D2 receptor antagonist, was developed as long-acting sustained-release microspheres with poly(lactide-co-glycolide) (PLGA) as a drug carrier for the treatment of schizophrenia. In the present study, the main objective is to determine the nonclinical safety profile of risperidone-loaded microspheres (RM) in Beagle dogs after intramuscular administration for 3 months, once in 2 weeks, followed by 8-week recovery phase. No animal death was found and no special toxicological findings were observed. The findings, such as hypoactivity, ptosis, increased heart rate, and elevated serum and pituitary prolactin levels, were observed and related to the pharmacological effects of risperidone. The changes in the reproductive system (uterus, ovary, vagina, cervix, and mammary gland) were considered secondary to the prolactin elevation, and the congestion of spleen was related to risperidone. The foreign body granulomas at injection sites might be caused by PLGA. At the end of recovery phase, the above changes mostly recovered to normal, and on administering 3 mg/kg dose level once in 2 weeks on Beagle dogs showed no observed adverse effect. Taken together, RM had exhibited the acceptable safety.

PCC0208009 enhances the anti-tumor effects of temozolomide through direct inhibition and transcriptional regulation of indoleamine 2,3-dioxygenase in glioma models

Indoleamine 2,3-dioxygenase (IDO), which is highly expressed in human glioblastoma and involved in tumor immune escape and resistance to chemotherapy, is clinically correlated with tumor progression and poor clinical outcomes, and is a promising therapeutic target for glioblastoma. IDO inhibitors are marginally efficacious as single-agents; therefore, combination with other therapies holds promise for cancer therapy. The aim of this study was to investigate the anti-tumor effects and mechanisms of the IDO inhibitor PCC0208009 in combination with temozolomide. The effects of PCC0208009 on IDO activity inhibition, and mRNA and protein expression in HeLa cells were observed. In the mouse glioma GL261 heterotopic model, the effects of PCC0208009 on l-kynurenine/tryptophan (Kyn/Trp), tumor growth, flow cytometry for T cells within tumors, and immunohistochemistry for IDO and Ki67 were examined. In the rat glioma C6 orthotopic model, animal survival, flow cytometry for T cells within tumors, and immunohistochemistry for proliferating cell nuclear antigen (PCNA) and IDO were examined. The results show that PCC0208009 is a highly effective IDO inhibitor, not only directly inhibiting IDO activity but also participating in the gene regulation of IDO expression at the transcription and translation levels. PCC0208009 significantly enhanced the anti-tumor effects of temozolomide in GL261 and C6 models, by increasing the percentages of CD3+, CD4+, and CD8+ T cells within tumors and suppressing tumor proliferation. These findings indicate that PCC0208009 can potentiate the anti-tumor efficacy of temozolomide and suggest that combination of IDO inhibitor-based immunotherapy with chemotherapy is a potential strategy for brain tumor treatment.